Time-dependent wave packet state-to-state dynamics of H/D + HCl/DCl reactions

The H/D + HCl/DCl (v(0) = 0, j(0) = 0) reactions were investigated in the gas phase using the reactant coordinate based time-dependent wave packet method on the BW2 PES [W. Bian and H.-J. Werner, J. Chem. Phys. 112, 220 (2000)]. The total and state-to-state integral and differential cross sections of both the abstraction and the exchange channels were reported over the energy range from threshold to 2.0 eV. The theoretical total exchange integral cross sections agree well with Volpp's experimental measurements but differ from Polanyi's experimental results for H + DCl reaction. The theoretical total abstraction integral cross sections are more than twice as large as the experimental results from the two groups for the H + HCl/DCl reactions. For the four isotope combinations, the total exchange integral cross sections increase monotonically with collisional energy while the abstraction integral cross sections start to decrease at relatively high collision energies. And the abstraction products are predominantly backward and sideways scattered while the exchange products are almost backward scattered. For the two channels, the D + HCl reaction presents the highest reactivity, the H + DCl reaction presents the lowest reactivity, and the H + HCl and D + DCl reactions are in between with the H + HCl reaction having a slightly larger reactivity.